Double-ended extension tool



FIG. 1 is a top perspective view of the claimed design for a double-ended extension tool;

FIG. 2 is a top view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a cross-section view of FIG. 3;

FIG. 5 is a left side view thereof;

FIG. 6 is a cross-section view of FIG. 5;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a bottom perspective view thereof. 

CLAIM The ornamental design for a double-ended extension tool, as shown and described. 